S1146 Mind-Gut Connection: Evaluating the Relationship Between the Use of Psychiatric Medications in Those Undergoing SIBO Testing

Introduction: Small intestinal bacterial overgrowth (SIBO) is the presence of excessive microbes in the small intestine and has been linked to psychiatric conditions like anxiety and depression. The relationship between mood disorders, their treatment with medications like selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), dopamine-norepinephrine reuptake inhibitor (DNRIs), tricyclic antidepressants (TCAs), monoamine oxidase inhibitors, and other drugs like gamma-aminobutyric acid agonist, antipsychotics, and benzodiazepines and rates of SIBO are poorly understood. This study aims to identify an association between the use of psychiatric medications and those undergoing SIBO testing. Methods: This is a retrospective case-control analysis identified 1,447 patients who underwent SIBO glucose breath testing between 2017 and 2023. All breath testing was completed with stringent pre-test preparation. We calculated the odds ratio (OR) by medication category for intestinal methanogen overgrown (IMO) and hydrogen SIBO (H-SIBO). We further evaluated the OR by comorbid obesity, type 2 diabetes, and gastric emptying study results. Chi square test was used to evaluate the significance of each combination. Results: Of 1,447 individuals who underwent SIBO breath testing 990 (68%) were IMO positive, 249 (17%) were H-SIBO positive. Of patients undergoing breath testing, 948 (65%) were found to be taking a psychiatric medication and 881 (93%) of these had a positive breath test, 174 (20%) and 707 (80%) for H-SIBO and IMO respectively. SNRI usage was associated with H-SIBO (OR 1.58, P = 0.018) positivity. Among patients with obesity, SNRI usage was similarly associated with higher rates of H-SIBO (OR 1.82, P = 0.043). Among patients with obesity, use of TCAs was associated with lower rates of H-SIBO (OR 0.31, P = 0.047). No association was found between rates of IMO and usage of any psychiatric medication. Conclusion: Our study found a significant relationship between H-SIBO and the use of SNRIs. Given the previously recognized association between psychiatric conditions and SIBO diagnosis, this association is not unexpected. However, since no association of increased SIBO incidence was noted among patients using SSRIs or DNRIs, this may represent a specific drug action. Additionally, the use of TCAs were associated with lower rates of SIBO diagnosis which given the utility of TCAs in functional abdominal conditions, could benefit this population and deserves further investigation. The correlations observed here are preliminary and must be further studied as we strive to understand the relationship between psychiatric conditions and medications and SIBO.